Can friends on different platforms join the same party with the bot?
Use the party and cross-platform options available to your Fortnite accounts and selected experience. The hosted bot does not require every friend to use the same browser device, and it cannot override restrictions shown by the game.
Separate the control screen from the game platform
A player can manage the web panel on a phone or computer while using Fortnite on a supported gaming device. The bot runs through the hosting service, so the device displaying the panel is not another player slot and does not determine which console your friend must use. Coordinate invitations in Fortnite as you normally would for those player accounts. Keep the website open where it is convenient to read, without assuming that a desktop browser is required for the group.
Check the account that receives the warning
If a friend cannot join across platforms, read the specific restriction shown to that player. Check the selected experience and the party permissions available on the accounts involved. The service's supported platform metadata for the bot is not a tool for bypassing account or platform policies. Changing an appearance setting or restarting the hosted connection cannot establish that a player's cross-platform permissions changed. Work through the visible game warning first so the group knows which condition remains unresolved.
Reconfirm the lineup after reconnecting
Different devices may return to their lobbies at different times after a connection interruption. Have the leader confirm who is present before issuing new invitations or pressing Ready. A friend reconnecting on a console and the owner reopening the browser may be separate events, even when they happen together. Check the current bot name and party list, then proceed with the activity supported by that arrangement. Successful party formation still does not guarantee a particular matchmaking result or the identity of opponents.